Math formulas, discoveries, or diagrams

Riemanns sums:

1. First, we pick some positive integer for N.
2. We now subdivide the interval interval into N equal subintervals.
3. There should be new subintervals after you do step 2. Each of the new subintervals has length
4. Label the endpoints of the new subintervals.
5. In each of the subintervals we pick a number xi and draw a line segment perpendicular to the x-axisfrom the point to a point on the graph.
6. Then construct rectangles which have the line segments as their height and the subintervals as their base.